Report of Solar Geophysical Activity

Joint USAF/NOAA Solar Geophysical Activity Report and Forecast
SDF Number 361 Issued at 2200Z on 26 Dec 2016

IA.  Analysis of Solar Active Regions and Activity from 25/2100Z to
26/2100Z: Solar activity has been at very low levels for the past 24
hours. There is currently 1 numbered sunspot region on the disk.
IB.  Solar Activity Forecast: Solar activity is expected to be very low
on days one, two, and three (27 Dec, 28 Dec, 29 Dec).

IIA.  Geophysical Activity Summary 25/2100Z to 26/2100Z: The geomagnetic
field has been at unsettled to minor storm levels for the past 24 hours.
Solar wind speed reached a peak of 742 km/s at 26/0142Z. Total IMF
reached 6 nT at 26/0522Z. The maximum southward component of Bz reached
-4 nT at 26/0458Z. Electrons greater than 2 MeV at geosynchronous orbit
reached a peak level of 26143 pfu.
IIB.  Geophysical Activity Forecast: The geomagnetic field is expected
to be at quiet to active levels on day one (27 Dec) and quiet levels on
days two and three (28 Dec, 29 Dec).

III.  Event probabilities 27 Dec-29 Dec
Class M    01/01/01
Class X    01/01/01
Proton     01/01/01
PCAF       green

IV.  Penticton 10.7 cm Flux
Observed           26 Dec 074
Predicted   27 Dec-29 Dec 074/075/075
90 Day Mean        26 Dec 080

V.  Geomagnetic A Indices
Observed Afr/Ap 25 Dec  012/018
Estimated Afr/Ap 26 Dec  018/022
Predicted Afr/Ap 27 Dec-29 Dec  007/008-006/005-006/005

VI.  Geomagnetic Activity Probabilities 27 Dec-29 Dec
A.  Middle Latitudes
Active                30/10/10
Minor Storm           10/01/01
Major-severe storm    01/01/01
B.  High Latitudes
Active                15/20/20
Minor Storm           30/20/20
Major-severe storm    40/10/10

**** SPACE WEATHER OUTLOOK ****

Summary For December 19-25

G2 (Moderate) storm levels were observed on 21 Dec due to the onset of coronal hole effects.

G1 (Minor) Storm levels were observed on 22 Dec as coronal hole effects persisted.

Outlook For December 26-January 1

G1 (Minor) conditions are expected on 26 Dec due to coronal hole effects.

No other significant space weather is expected.